Strapping retainer for lading and method for using the same
A retainer having an elongated body secures one end of a cargo-engaging strapping to a wall anchor of a cargo transport unit wall. In operation, a loop is formed in the strapping and passed from a first side of the anchor to a second side, where the retainer is inserted within the loop, such that the loop engages a portion of a strapping-engaging surface of the retainer body. Then the loop is pulled toward the anchor until the retainer seats against the anchor. Finally, the portion of the strapping extending from the first side is pulled toward the second side, whereby a loose end of the loop is secured against the anchor. The retainer prevents strapping slippage along the anchor, which preserves the tension in the strapping and prevents the cargo from shifting and becoming damaged. The retainer also allows for improved application and removal of the strapping.
1. Field of the Invention
This invention generally relates to a retainer and method for securing cargo, using strapping, onto cargo transport units having wall anchors. A retainer is used with strapping and a wall anchor to decrease the occurrence of strapping slippage and potential subsequent cargo damage. The retainer also provides for decreased application and removal time and a safer removal process. The method uses a retainer to quickly secure cargo and to prevent strapping slippage and potential subsequent cargo damage. Special application is found for this approach in securing wide rolls of printing paper transported by boxcar.
2. Description of Related Art
According to standards issued by the Association of American Railroads (“AAR”) in publications such as General Information Series No. 681; “Wide Roll Printing Paper Secured by 1½″ Wide Polyester Cord Straps in Cushion Equipped Boxcars,” which is hereby incorporated herein by reference, wide rolls of printing paper transported by boxcar are to be secured with a plurality of 1.50 inch wide polyester cord straps which are secured to the boxcar sidewalls by wall anchors or lading tie anchors. One end of a strap is wrapped around a wall anchor three times and knotted, in order to prevent disengagement of the strap from the anchor. Once the rolls are loaded, the straps from opposite sides of the boxcar are joined together and tensioned with a buckle to securely grip the rolls.
One problem with the above-described process is that there can be slippage and stretching of the polyester straps. Sudden movements of the boxcar cause lading such as the rolls of this AAR standard to exert substantial force on the lading, which applies force against the polyester straps. If not properly secured, the lading will shift. When the knot system is used, this applied force causes the knots to tighten and slip. Eventually, the knots slip toward the wall anchors and become tightly wedged between the anchor and the wall. As a result of this slipping, several inches of slack are added to the straps and they cease to tightly grip the lading, which allows the lading to more easily shift, become damaged, or even fall.
Another problem with using knots to secure the polyester straps is that the initial application process is lengthy, as is the removal process. According to AAR standards, the strap must be wrapped around the wall anchor three times before it is knotted. This can require constant readjustment to ensure that a proper length of strap extends beyond the anchor, such that it can be tied in a knot. The removal process is even more lengthy, because the knots become wedged behind the anchors and must be removed with a knife or similar cutting instrument or the knot and strap can be burned off. In most instances, a ladder must be used to reach the higher straps and it is especially time-consuming and cumbersome, if not dangerous, to use a knife or fire to remove the knots while standing on a ladder.
Accordingly, a general object and aspect of the present invention is to provide a cargo-securing device for use with strapping and existing wall anchors of a cargo car or other cargo transport unit.
Another object or aspect of this invention is to provide a cargo-securing device which reduces the amount of cargo damage resulting from strapping slippage caused by knots tightening, stretching, and slipping behind wall anchors and the like during transport.
Another object or aspect of this invention is to provide a cargo-securing device which can be easily and safely applied and removed from the strapping and wall anchors for securing the strapping.
Another object or aspect of this invention is to provide a cargo-securing device which is sufficiently simple and inexpensive to be disposable.
Another object or aspect of this invention is to provide a cargo-securing method which eliminates the need to use a knot to secure strapping to wall anchors for transport of cargo such as wide rolls of printing paper in a boxcar or the like.
Other aspects, objects and advantages of the present invention, including the various features used in various combinations, will be understood from the following description according to preferred embodiments of the present invention, taken in conjunction with the drawings in which certain specific features are shown.SUMMARY OF THE INVENTION
In accordance with the present invention, a strapping retainer reduces the amount of strapping slippage when installed for the purpose of restraining lading in a cargo transport unit, especially a rail car. The strapping retainer makes it possible to eliminate the knot typically associated with the wall anchor. The strapping retainer has a body with a top end, a bottom end, and a strapping-engaging surface connecting the two ends. The retainer body fits into a loop of a strapping length at one side of a wall anchor and is configured and sized such that it resists becoming wedged behind the wall anchor when it and the loop are pulled toward the wall anchor during transport of cargo. Strapping slippage is virtually eliminated, because there is no knot which can tighten and become wedged behind the wall anchor, thereby elongating the effective strapping length after installation. Furthermore, the retainer may be formed of a lightweight plastic which resists deformation, but is inexpensive and disposable.
A cargo-securing method uses the described retainer to reduce or eliminate strapping slippage at the wall anchor and resulting strapping elongation after being installed to restrain cargo or lading. A loop is formed in the strapping, then inserted behind the wall anchor, from a first side of the anchor to a second side. A retainer is inserted into the strapping loop and the strapping is pulled back toward the first side until the retainer seats adjacent to the anchor or is otherwise prevented from further movement toward the anchor. Finally, the strapping is pulled around the front of the anchor toward the second side to develop a pinch-point condition, then this strapping is secured to another strapping length using a conventional buckle such as a disposable turnbuckle.BRIEF DESCRIPTION OF THE DRAWINGS
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention and virtually any appropriate manner.
The illustrated preferred embodiment of
The height of the body portion 12 is not critical, although a relatively short body portion 12 is preferable for some anchor configurations. For example,
The knurls 17 illustrated in
Ears 18 can be provided when desired. The primary function of the ears 18 is to temporarily secure the retainer 10 to the strapping 24 before the strapping 24 is tightened. Once the strapping 24 is tightened it will hold the retainer 10 in place, so the function provided by the ears 18 is no longer needed. In the illustrated embodiments of
In the illustrated embodiments having vertical extensions 19, the vertical extensions 19 are generally flush with the strapping-engaging surface 14 and extend away from the top and bottom ends 22 of the body portion 12. These vertical extensions 19 of the two ears 18 are sized such that the space between the horizontal extensions 20 is slightly wider than the width of the strapping 24.
Each horizontal extension 20 is sized such that the space between the associated vertical extension 19 and overhang 21 is slightly wider than the thickness of the strapping 24. The illustrated overhangs 21 extend toward each other to effectively form opposing hooks which are capable of engaging the strapping 24. Hence, from the preceding description, it can be seen that the ears 18 are configured and oriented to form hooks which cooperate to define an open channel into which the strapping 24 can be slid or otherwise inserted when the retainer 10 is initially applied. Alternative embodiments are possible, such as a single top ear or top and bottom ears 18 which are connected by a bridge 23, illustrated in phantom in
Referring back to
During transport, the cargo is generally stationary in the storage area of the cargo transport unit once it has been secured by lengths of strapping. However, sudden movements of the cargo transport unit will cause the cargo to shift and apply force to the strapping lengths. In the knot system according to existing AAR standards, this applied force translates into knot slippage and strapping stretching. The slipping of the knot is much more problematic than the stretching of the strapping, because the polyester strap according to existing AAR standards has elastic properties which return it to an unstretched configuration after the removal of the applied force. On the other hand, the slack in the strap caused by knot slippage remains even after the applied force is removed and the cargo becomes inadequately secured. The present invention eliminates slippage, thereby limiting any strapping displacement to temporary strapping stretching.
The receptor loop 34 is passed through the area defined by the wall anchor flanges 30, the wall anchor tie bar 40, and the sidewall depression 26. As shown in
With the retainer 10 inside the receptor loop 34, the strapping 24 is pulled toward the end wall side 36 until the retainer 10 seats within the sidewall depression 26, adjacent to the tie bar 40, and between the anchor flanges 30. This configuration is illustrated in
The retainer 10 is sized such that it does not pass behind the tie bar 40 as it is pulled toward the end wall side 36. Further, the retainer 10 is preferably formed of a relatively non-deformable material so that it will not deform and become wedged behind the tie bar 40. Any material which would become perceptibly deformed by a 3,500 pound load in operation is considered to be inappropriate. It is believed that material having a flexural modulus greater than 500 kpsi is sufficiently non-deformable for forming the retainer 10. In particular, we have found that a retainer 10 formed of a 33% glass-filled nylon polymer (flexural modulus of 1,350 kpsi) or a 30% glass-filled nylon polymer (flexural modulus of 1,230 kpsi) is adequate, but one formed of material such as Texin® 260 (flexural modulus of 43 kpsi) or Texin® 4210 (flexural modulus of 100 kpsi) is not and will deform as a result of the forces to which the retainer 10 is typically subjected during transport. As will be appreciated by one skilled in the art, a retainer 10 formed of a material such as 33% glass-filled nylon polymer or 30% glass-filled nylon polymer is strong enough to be used repeatedly, yet inexpensive enough to be disposed along with the used strapping.
After the retainer 10 has become seated against the anchor 28, the loose end 42 and long end 44 of the strapping 24 are pulled across the front of the tie bar 40 toward the doorway side 38. This configuration is illustrated in
To summarize, slippage is reduced by the above-described application process, because the strapping secures a loose end of the initial loop against the wall anchor. Slippage is further reduced by providing a retainer which is sufficiently sized, such that it resists becoming wedged behind the wall anchor and also provides a second area at which the strapping secures the loose end of the initial loop. It has been observed that slippage is essentially eliminated and the only slack in the strapping is the result of the temporary stretching of the strapping itself. Therefore, the strapping remains well-contoured to the cargo and the risk of damage to the cargo is greatly reduced. It will be appreciated that the described application process can be accomplished much quicker than the known knot system.
It will be seen that use of the knot system results in approximately 5.25 inches of displacement between the clamps when a 3,000 pound load is applied to the strap. At the same applied force, the mark moved approximately four inches, which is equal to the amount of knot slippage. These four inches of slack in the strap remain after the force is removed and the strap returns to near its original length. When in use, this slippage causes the cargo to become relatively unsecured. Furthermore, there are a total of eight inches of slack in operation, because there are two straps connected across the width of the boxcar by a buckle. Therefore, the risk of cargo damage is greatly increased, because the cargo will not be well-supported by the straps, allowing for further shifting of the cargo.
On the other hand, for the same 3,000 pound load, there was only approximately one inch of displacement between the clamps for the retainer system. Additionally, the mark did not become displaced when the retainer was used, which indicates that the retainer system virtually eliminates slippage. Thus, the only element of displacement associated with use of the retainer system is the unavoidable stretching of the strap itself, which is approximately one inch at 3,000 pounds of applied force for strapping of this length. As previously explained, this strapping stretching is temporary and the strapping returns to its unstretched length and tension once the applied force is removed. Hence, the straps remain well-contoured to the cargo and the risk of cargo damage is greatly decreased.
In further contrast to the known knot system or other cargo-engaging strapping securing systems, the present invention also allows for quick and safe removal of the lengths of strapping after transport. The retainer 10 does not become wedged behind the wall anchor 28, so the retainer 10 and strapping 24 can be simply backed out of the anchor 28. In use, once the cargo has reached its destination, the strapping 24 is typically cut away from the buckle and the strapping 24 and retainer 10 can be backed out of the sidewall depression 26 to a condition approximating that shown in
It is possible, of course, after the strapping retainers have been removed from the wall anchors, that some will accidentally be left behind in the cargo transport unit. If the unit is drably colored, dark or poorly lit, then there is a possibility that a person could not notice such a retainer lying on a floor or other horizontal surface and inadvertently step on one and slip or otherwise result in compromised footing. Accordingly, the strapping retainer preferably is made of or includes a material that is highly visible in low light conditions in order to provide an enhanced visibility strapping retainer. Such is referred to herein as an “enhanced visibility characteristic,” which can be achieved by making the retainer of brightly colored or fluorescent or phosphorescent material or have reflective surface features or have some other material or feature which enhances visibility and makes the retainer more readily visible within a cargo transport unit. In a preferred embodiment, the strapping retainer is made of a bright red material. Alternatively, rather than using such a material, it is instead possible to apply a surface treatment, such as a coating or tape, to all or part of the retainer such that it is readily visible within a darkened cargo transport unit.
It will be understood that the embodiments of the present invention which have been described are illustrative of some of the applications of the principles of the present invention. Numerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention, including those combinations of features that are individually disclosed or claimed herein.
1. A lading strapping retainer for use in combination with a strapping length and a cargo transport unit wall having an associated wall anchor, the lading strapping retainer comprising:
- an elongated body portion having a top end, a bottom end, and a strapping-engaging surface connecting said top end and said bottom end, wherein said body portion comprises a generally non-deformable material and is configured and sized such that it cannot fit between the cargo transport unit wall and the associated wall anchor when a portion of the strapping-engaging surface is engaged by a strapping length.
2. The lading strapping retainer of claim 1, wherein said generally non-deformable material has a flexural modulus of at least about 500 kpsi.
3. The lading strapping retainer of claim 1, wherein said generally non-deformable material comprises a filled nylon polymer.
4. The lading strapping retainer of claim 1, wherein said generally non-deformable material comprises a glass-filled nylon polymer.
5. The lading strapping retainer of claim 1, wherein said generally non-deformable material comprises a filled nylon polymer having at least 30 weight percent glass filling, based on the total weight of the filled polymer.
6. The lading strapping retainer of claim 1, wherein said strapping-engaging surface is smoothly shaped.
7. The lading strapping retainer of claim 1, wherein said strapping-engaging surface has a generally circular profile.
8. The lading strapping retainer of claim 1, wherein said strapping-engaging surface has a generally teardrop-shaped profile.
9. The lading strapping retainer of claim 1, wherein the distance between said top end and said bottom end of the retainer is less than the width of the strapping length.
10. The lading strapping retainer of claim 1, wherein said strapping-engaging surface includes a plurality of raised knurls.
11. The lading strapping retainer of claim 1, wherein at least a portion of the lading strapping retainer has an enhanced visibility characteristic.
12. A lading strapping retainer for use in combination with a strapping length and a cargo transport unit wall having an associated wall anchor, the lading strapping retainer comprising:
- an elongated body portion having a top end, a bottom end, and a strapping-engaging surface connecting said top end and said bottom end, wherein said body portion is configured and sized such that it cannot fit between the cargo transport unit wall and the associated wall anchor when a portion of the strapping-engaging surface is engaged by a strapping length; and
- an ear extending from said top end, wherein said ear is capable of engaging the strapping length and supporting the body portion.
13. The lading strapping retainer of claim 12, wherein said ear includes a horizontal extension extending away from said body portion, and an overhang associated with and extending away from said horizontal extension, such that said ear defines a hook.
14. The lading strapping retainer of claim 13, said ear further comprising a vertical extension associated with said horizontal extension and extending away from the top end of the body portion.
15. The lading strapping retainer of claim 12, further comprising another ear extending from said bottom end and generally aligned with said ear extending from the top end.
16. The lading strapping retainer of claim 15, wherein said ears cooperate to form an open channel for engaging the strapping length.
17. The lading strapping retainer of claim 15, wherein said ears connect to form a closed channel for engaging the strapping length.
18. A cargo-securing system, comprising:
- a cargo transport unit having walls and a plurality of wall anchors associated with and spaced apart from said walls;
- a strapping length positioned between one of said wall anchors and one of said walls and forming a receptor loop on a first side of said wall anchor; and
- a strapping retainer positioned within and engaging said receptor loop of the strapping length, wherein said strapping retainer comprises an elongated body portion having a top end, a bottom end, and a strapping-engaging surface connecting said top end and said bottom end, wherein said body portion is configured and sized such that it cannot fit between the cargo transport unit wall and the associated wall anchor when a portion of the strapping-engaging surface is engaged by the strapping length.
19. The cargo-securing system of claim 18, wherein said cargo transporting unit is a railway boxcar.
20. A combination of cargo and a cargo-retaining system, comprising:
- a cargo transport unit having a storage area which includes walls and a plurality of wall anchors associated with and spaced apart from said walls;
- cargo positioned within said storage area of the transport unit;
- a strapping length positioned between one of said wall anchors and one of said walls and forming a receptor loop on a first side of said wall anchor;
- a strapping retainer positioned within and engaging said receptor loop of the strapping length, wherein said strapping retainer comprises an elongated body portion having a top end, a bottom end, and a strapping-engaging surface connecting said top end and said bottom end, wherein said body portion is configured and sized such that it cannot fit between the wall and the associated wall anchor when a portion of the strapping-engaging surface is engaged by the strapping length; and
- said strapping length engages the cargo and secures the cargo in place by restraining its movement within the storage area.
21. A method of securing a strapping length to a wall of a cargo transport unit having an associated wall anchor with a front portion and a rear portion, the method comprising:
- forming an initial loop in an end of the strapping length, wherein said initial loop comprises a receptor loop and a loose end;
- passing the receptor loop through a space defined by the wall and the rear portion of the associated wall anchor from a first side of the wall anchor to a second side of the wall anchor, such that said loose end and a long end of the strapping length remain at the first side, wherein said long end is disposed between the wall and said loose end;
- placing a retainer having a body with a strapping-engaging surface within said receptor loop, such that said receptor loops wraps around a portion of said strapping-engaging surface;
- pulling the strapping length toward said first side until said receptor loop tightens about said strapping-engaging surface and said retainer seats adjacent to the wall anchor; and
- wrapping said loose end and said long end around the front portion of the wall anchor toward said second side, such that said loose end is tightly secured between said long end and the wall anchor.
22. The method of claim 21, wherein pulling the strapping length toward the first side includes orienting the retainer such that a portion of the strapping-engaging surface extends away from the wall beyond the front portion of the wall anchor when the retainer seats adjacent to the wall anchor.
23. The method of claim 22, wherein wrapping said loose end and said long end around the front portion of the wall anchor includes securing the loose end at a second securing area spaced apart from said wall anchor.
24. The method of claim 23, wherein said second securing area is between said long end and said receptor loop.
25. The method of claim 21, further including a step of securing said long end to a buckle.
International Classification: B61D 3/16 (20060101);